The prior art two component adhesives composed of a prepolymer component and a curative component usually have been mixed at ratios of at least 4:1, and in many instances much higher. Also because the two components are mixed at such relatively high ratios those of ordinary skill in the art have used fillers to aid in controlling the ratio and to control sag resistance but this technique resulted in the physical properties of the adhesives varying in proportion to the fillers added to the adhesive. Also the aged curative is relatively moisture sensitive.
Recent discoveries have provided a two component sag resistant adhesive where the components are mixed at 1:2 to 2:1 ratio with a gel time of 2 to 120 minutes at 24.degree. C., relatively low viscosity and good bonding ability to metal and polyester substrates.
The prior art two component adhesives used in the polyester impregnated fiberglass molded products industry generally have contained high filler loadings with powdery fumed silica being greatly preferred as a filler. With the energy crisis and with greatly increasing fuel costs the price of this preferred filler of powdery fumed silica has increased in like manner. Thus it is desirable to replace powdery fumed silica in some manner with other fillers or eliminate filler altogether as the powdery fumed silica affects the adhesive viscosity and its sag resistance.